In-flight communications system

ABSTRACT

An in-flight communications system and method suitable for discrete use by, e.g., an Air Marshal, includes a personal digital assistant (PDA) device having wireless communications capabilities, an aircraft cabin wireless local area network (LAN) within which the PDA device can operate, a communications management unit (CMU) associated with the wireless LAN and operable to send and receive data via ACARS, and an operations center operable to receive data that is generated by the PDA, transmitted over the wireless LAN and passed to the operations center via ACARS.

PRIORITY CLAIM

This application claims the benefit of U.S. Utility Application Ser. No.10/646,925 filed on Aug. 25, 2003, which itself claims priority fromU.S. Provisional Application Ser. No. 60/457,598, filed Mar. 27, 2003,both of which are expressly incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates to improvements in communications systems.More particularly, the present invention relates to an in-flightcommunication system that allows users to send and receive messages inan inconspicuous manner, which is especially desirable for personnel,such as airline security Air Marshals, who expect to remain discrete.

BACKGROUND OF THE INVENTION

In recent years, Air Marshals have become more prevalent on commercialairlines in view of the increased security measures necessitated by thethreat of terrorism and general increased desire for public safety. Tobe effective, Air Marshals should preferably be able to communicate witheach other, with the flight deck and/or with their command and controlcenters on the ground. All of these types of communication shouldpreferably be possible from any seat on the aircraft, or indeed, fromvirtually any place on the aircraft. Also, any data communication shouldpreferably be transmitted in a secured and covert mode. Heretofore,however, systems have not been fielded that embody these capabilities,let alone in a comprehensive and seamless manner. Accordingly, thereremains a need to provide improved in-flight communication capabilities.

SUMMARY OF THE INVENTION

The present invention provides a substantially comprehensive andseamless system for in-flight communications by leveraging existingtechnology in a manner not previously contemplated. Specifically, thepresent invention provides a system whereby an Air Marshal, for example,traveling on an air transport aircraft almost anywhere in the world cancommunicate with ground operations personnel to, e.g., report an onboardincident or receive information from the ground that is critical to hismission. The present invention also enables the Air Marshal tocommunicate with other Air Marshals that may be onboard the sameaircraft, as well as to communicate with the aircraft flight deckofficers and the cabin crew. Significantly, the system of the presentinvention is preferably configured such that the Air Marshal can sendand receive messages in an inconspicuous manner, thereby protecting hisundercover status.

While the present invention finds particular utility in connection withairline safety and security by providing secure and covertcommunications capabilities to personnel such as Air Marshals, thepresent invention can also be used by airlines for operationalefficiency. For example, cabin crews can use the system to communicatewith their ground operations centers to request cabin maintenanceactions or consumable replenishments at a next stop, or request/receiveconnecting gate information.

In a preferred embodiment, the present invention comprises an AirMarshal terminal, such as a Personal Digital Assistant (PDA) device(e.g., a Palm Pilot) with a wireless modem, a Communication ManagementUnit (CMU), access to the Aircraft Communications Addressing andReporting System (ACARS), and a ground host. The ACARS and ground hostsare presently available and well-known to those skilled in the art, andexist on commercial airlines and through service providers such asARINC. The present invention leverages these facilities by layeringthereon secure communications using an encryption scheme that encryptsthe data transmissions, and providing a wireless network installed onthe aircraft. The wireless network preferably operates in accordancewith a commercial standard such as IEEE 802.11(b).

In operation, an Air Marshal, or other user, operates his PDA in aconventional manner, at least to those who may casually see such use.However, in accordance with the present invention, the PDA includes awireless modem via which the PDA can communicate with the on-boardwireless network that operates in conjunction with the CMU, which inturn, is in communication with ACARS, thereby providing groundconnectivity, as well connectivity to other similarly-configured PDAsand to flight deck personnel.

The foregoing and other features of the present invention and theattendant advantages thereof will be more fully understood upon readingthe following detailed description in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred and alternative embodiments of the present invention aredescribed in detail below with reference to the following drawings:

FIG. 1 depicts an exemplary network architecture for implementing acommunication system in accordance with the present invention; and

FIGS. 2 and 3 depict exemplary screen shots of a PDA configured tooperate in a communication system in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the present invention preferably comprises an AirMarshal terminal 101, such as a personal digital assistant (PDA) device(such as a Palm Pilot) with a wireless modem, a Communication ManagementUnit (CMU) 105, part of the Aircraft Communications and AddressingRouting System (ACARS) 109, and a ground host 113. ACARS 109 and groundhost 113 are presently available and well-known to those skilled in theart, and exist on commercial airlines and via service providers such asARINC. The present invention leverages these facilities by layeringthereon secure communications using an encryption scheme that encryptsthe data transmissions, and providing a wireless network installed onthe aircraft. The wireless network preferably operates in accordancewith a commercial standard such as IEEE 802.11(b). Encryption technologyis well-known in the art and will not be described herein, except tonote that any level of encryption may be implemented that can besupported by the available bandwidth through ACARS/ARINC or any otherprotocol or service over which data generated by the present inventionis carried.

The use of wireless PDA 101 by an Air Marshal allows the officer (or anyauthorized user) to blend with the other passengers and not call undueattention to himself. Use of wireless PDA device 101 also allows theofficer to roam anywhere in the cabin and maintain secure communicationlinks. Using custom drop down menus (examples of which are shown inFIGS. 2 and 3), the officer can quickly send secure communications tothe flight deck, other Air Marshals on the aircraft and to his commandcenter, as well as receive secure data from the command center, otherAir Marshals, and the pilots. Security for communications isparticularly desirable due to the following threats:

-   -   ACARS messages are readable while in transit    -   Messages provide identification, location and time    -   “Bogus” messages can be transmitted and appear to be legitimate    -   Valid messages may be altered before delivery    -   Permits one entity to assume the role of another and engage in        communications    -   Limitations in addressing may result in delivery of message to        wrong recipient

Air Marshals communications requirements that are met by the presentinvention include communications between an Air Marshal and GroundOperations. Such communication might include, for example, informationregarding an incident on a given aircraft, or incidents on otheraircraft that is relayed to the Air Marshal. The present invention alsoprovides an Air Marshal the ability to communicate with other AirMarshals on the same aircraft, flight deck officers and other cabincrew. Such communication allows for better coordination on responses toonboard situations.

In view of the use of ACARS, the present invention further allows an AirMarshal to have air to ground communication coverage along all, orsubstantially all, air transport routes. In addition, the system inaccordance with the present invention provides inconspicuous operationand “information assurance” in the sense that there is provided Secure(Encrypted) Communications, Authenticated Communications and MessageIntegrity.

Referring again to FIG. 1, the present invention preferably comprises anelectronic system that is composed of both hardware and software.Significant components of the system include:

(1) personal digital assistant (PDA) 101 with a wireless communicationstransceiver (not shown);

(2) a cabin wireless local area network (LAN) unit (CWLU) (not shown);

(3) a communications management unit (CMU) 105 or communicationsmanagement function (CMF) software with Secure ACARS and/or ATN Securityfunctionality;

(4) a cockpit display unit and printer (not shown);

(5) at least one of a VHF data link 121, HF data link 123, and/or SATCOMdata link 125;

(6) an ACARS, ATN, and/or future aeronautical data link network 109; and

(7) a ground system 113 connected to data link network 109, and havingat least one display terminal 133. By combining these components asdescribed in more detail below, an Air Marshal can communicate fromvirtually any location on an aircraft 107 via wireless PDA 101 throughan aeronautical data link 109 with worldwide coverage in a secure andinconspicuous manner, thereby protecting the undercover nature of theAir Marshal's mission.

FIG. 1 depicts an exemplary network architecture for implementing asystem in accordance with the present invention. At a high level thepresent invention provides, in one embodiment, an aircraft securityenvelope 2 that incorporates a wireless LAN that is in communicationwith an ACARS security envelope 4, which is in turn, in communicationwith, e.g., a Transportation Safety Administration (TSA) securityenvelope 6. As shown, the system comprises:

Personal digital assistant (PDA) 101 with the wireless (IEEE 802.11)transceiver. This is a commercially available product that is preferablyconfigured with custom software to manage message entry display pages aswell as display information sent from other users within the system.Multiple PDAs 101 can be used in the system for other users such asother Air Marshals and the cabin crew.

(2) Cabin wireless local area network (LAN) unit (CWLU) serves as anaccess point for wireless (IEEE 802.11) transmissions and converts theminto, e.g., an Ethernet format, which is the interface into thecommunications management unit (CMU) 105.

(3) CMU 105 preferably includes Secure ACARS software and/or ATNSecurity software and is preferably integrated with a basic CMU thatfurther includes the capability of providing data security for allair-to-ground data link messages. The Secure ACARS software preferablyprovides, using known techniques, the security services ofconfidentiality (encryption), data authentication, and data integrity.Those skilled in the art will appreciate that a CMU is not critical tothe present invention and is used herein only to show an exemplaryimplementation. For example, communications systems are presently beingfielded that do not necessarily rely on the functionality of a CMU. Forinstance, a direct satellite link is one type of system that mightbypass the CMU. Similarly, an airphone system that communicates directlywith ground stations (and bypasses a CMU) could also be employed inconnection with the present invention.

(4) In a preferred implementation, CMU 105 interfaces to cockpitdisplays and printers which serve as communication terminals for theflight deck officers, as well as to a VHF data link radio (VDR) 141, HFdata link radio (HFDR) 143, and SATCOM data unit (SDU) 145 to provideconnectivity to the ACARS, ATN, or future aeronautical data links.

(5) A satellite 151, Satellite Earth Station 152, VHF Ground Stations(GS) 154, HF Ground Stations 156, air-ground network 127, a data linkservice provider ACARS Central Processing System (CPS) 158 and aterrestrial network 159 constitute a typical data link network thatprovides digital message communications capability between aircraft 107and ground users.

(6) Ground host/TSA Operation Center 113 preferably has peer SecureACARS software to provide the complementary data security service asperformed in CMU 105 with Secure ACARS.

(7) Finally, computer workstations 133 along with TSA Operations Center113 permit ground personnel to send and receive communications to andfrom the airborne Air Marshals.

Since the Air Marshal is provided a Communications Terminal that ispreferably in the form of a wireless PDA, the Air Marshal can easilyroam throughout the aircraft cabin and maintain a communications link.Such a PDA further allows the Air Marshal to blend into the passengerpopulation, since the “terminal” looks like a typical passenger'spossession. Such a terminal further enables the Air Marshal to receiveand transmit easily with minimal interaction or data entry. In otherwords, PDA 101, as used in the context of the present invention, givesan Air Marshal anonymity and roaming, both of which are significantcomponents of mission success.

FIGS. 2 and 3 are exemplary screen shots of possible displays that canbe presented to an Air Marshal on his PDA. FIG. 2 depicts exemplaryscreens that are particularly suited to Air Marshal duties. Thesescreens list types of incidents and other information about evolvingemergency scenarios. In a preferred implementation, the screens areadvantageously arranged to require only simple tap and clickfunctionality, thereby freeing the Air Marshal from excess work.

FIG. 3 depicts exemplary screen shots that could be presented on PDA 101when the system of the present invention is used to augment or enhanceexisting flight operations capabilities. In the case shown in FIG. 3,the screens show flight information and flight schedule informationprovided, e.g., by a particular airline.

As those skilled in the art will appreciate, there are tradeoffs inselecting the type of terminal that an Air Marshal might use. There aretwo basic choices: Data (e.g., a PDA) or Voice.

The following characteristics are associated with a PDA (DataCommunication):

-   -   Preformatted data entry screens allows for quick and complete        standard messages    -   Ability to uplink and downlink messages and graphics    -   Multiplex use of existing aircraft data link equipment    -   Worldwide coverage    -   Ground system required at headquarters for messaging

The following characteristics are associated with Voice Communication:

-   -   Not as discrete as text messaging    -   Easily overheard—Draws attention to Air Marshal    -   Unable to graphically convey the situation    -   Requires a dedicated voice channel from aircraft    -   Additional radio and antenna on aircraft    -   Additional spectrum/frequency allocation    -   Additional ground stations

In view of the foregoing, the present invention is preferably based ondata-type communication. However, to the extent voice communications canbe kept discrete and be operated without significant aircraft orcommunication facilities modifications like those mentioned above, thepresent invention can also be augmented to support speech capabilities.Further, in view of the use of a PDA, wireless airborne network andair-to-ground connectivity consistent with the principles of the presentinvention, information assurance is provided in the forms of:

-   -   Data Authentication—Provides strong authentication of the        terrestrial and airborne communicating peer entities    -   Data Integrity—Provides end-to-end data integrity for the        payload in uplink and downlink messages    -   Confidentiality—Provides end-to-end data confidentiality for the        payload in uplink and downlink messages

Likewise, the present invention provides cryptographic strength bypreferably implementing cryptographic algorithms and key length(s)suitable for protecting civilian “For Official Use Only” (FOUO) andmilitary “Sensitive-But-Unclassified” (SBU) data.

With reference to FIG. 1, the flow of a typical Air Marshalcommunication message is as follows:

Message Uplink

-   -   Ground user composes message to aircraft    -   Secure ACARS Ground System protects message at TSA Operations        Center    -   Protected message transits terrestrial networks to ACARS Data        Link Service Provider    -   Protected message transits DSP ground—ground and air-ground        networks to aircraft    -   CMU authenticates ground user, decrypts message, forwards to Air        Marshal via protected IEEE 802.11 message, and displays message        on flight deck Multi-function Control and Display Unit (MCDU),        if authorized    -   PDA or any other portable device receives, via CMU 105, IEEE        802.11 message and decrypts for user    -   PDA or other portable device alarms/notifies user of incoming        message

Message Downlink

-   -   Air Marshal composes message on PDA using predefined message        structure or free text entries    -   PDA transmits protected IEEE 802.11 message to CMU    -   CMU encrypts message, transmits message via ACARS network, and        displays message on flight deck Multi-function Control and        Display Unit (MCDU), if authorized    -   Protected message transits ACARS air—ground and ground—ground        networks to DSP    -   DSP forwards protected message to TSA Operations Center via        ground—ground network    -   Operations Center authenticates Air Marshal and decrypts message

Those skilled in the art will appreciate that while the function ofencrypting and decrypting is performed by the CMU, the PDA device itselfcould also perform these functions as long as the appropriate keys andprocessing power were available to the device.

In view of the architecture and components employed in a system inaccordance with the present invention, it is possible to significantly,if not completely, eliminate the following threats that Air Marshals andtheir colleagues face:

-   -   Disclosure—Messages are readable while in transit    -   Traffic Analysis—Messages provide identification, location, and        time    -   Spoofing—Bogus messages can be transmitted and appear to be        legitimate    -   Modification—Valid messages may be altered before delivery    -   Masquerade—Permits one entity to assume the role of another        entity and engage in communications    -   Mis-delivery—Limitations in addressing may result in delivery of        messages to wrong recipient

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be apparent toone of ordinary skill in the art in light of the above disclosure. Thescope of the invention is to be defined only by the claims appendedhereto, and by their equivalents.

Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

1. An in-flight communications system, comprising: an aircraft cabinenvelope including a wireless LAN; a personal digital assistant (PDA)that is in wireless communication with the aircraft cabin envelope; anACARS security envelope that is in communication with the wireless LANvia an airborne communications management unit (CMU); and a ground-basedsecurity envelope that is in communication with a ground-based segmentof the ACARS security envelope thereby to transmit and to receiveinformation sent between the ground-based security envelope and thepersonal digital assistant.
 2. (canceled)
 3. The system of claim 1,wherein the wireless LAN supports a plurality of wireless devices. 4.The system of claim 1, wherein the ACARS security envelope comprises adatalink service provider that is linked to the ground based securityenvelope.
 5. The system of claim 1, wherein an authorized user operateswithin the aircraft cabin security envelope.
 6. The system of claim 5,wherein the authorized user communicates with an operations centerwithin the ground-based security envelope.
 7. The system of claim 5,wherein the authorized user communicates with flight deck personnel onthe same aircraft.
 8. The system of claim 5, wherein the authorized usercommunicates with another Air Marshal on the same aircraft.
 9. Anin-flight communications system, comprising: a personal digitalassistant (PDA) device having wireless communications capabilities; anaircraft cabin wireless local area network (LAN), the PDA device beingoperable to be in communication with the wireless LAN; a communicationsmanagement unit (CMU) associated with the wireless LAN and operable tosend and received data via ACARS; and an operations center operable toreceive data generated by the PDA, transmitted over the wireless LAN andpassed to the operations center via ACARS.
 10. The system of claim 9,wherein the CMU provides PDA generated data to flight deck personnel.11. The system of claim 9, wherein the PDA device is programmed withpredetermined screens.
 12. The system of claim 11, wherein the screensare arranged to have tap and send functionality.
 13. The system of claim9, wherein the PDA device is operable to communicate with another PDAdevice over the wireless LAN. 14-26. (canceled)
 27. An in-flightcommunications system, comprising: a personal digital assistant (PDA)device having wireless communications capabilities; an aircraft cabinwireless local area network (LAN), the PDA device being operable to bein communication with the wireless LAN; a communications moduleassociated with the wireless LAN and operable to send and receive datavia an air-to-ground communications system; and an operations centeroperable to receive data generated by the PDA, transmitted over thewireless LAN and passed to the operations center via the air-to-groundcommunications system.
 28. The system of claim 27, wherein thecommunications module comprises a communications management unit (CMU).29. The system of claim 27, wherein the air-to-ground communicationssystem comprises an ACARS.
 30. The system of claim 27, wherein thecommunications module provides PDA generated data to flight deckpersonnel.
 31. The system of claim 27, wherein the PDA device isprogrammed with predetermined screens.
 32. The system of claim 31,wherein the screens are arranged to have tap and send functionality. 33.The system of claim 27 wherein the PDA device is operable to communicatewith another PDA device over the wireless LAN.